Cleaning agents comprising an anionic surfactant and a skin-protecting component

ABSTRACT

CLEANING AGENTS COMPRISING ANIONINC SURFACTANTS WHICH MAY TEND TO IRRITATE THE SKIN IN ADMIXUTRE WITH A SKINPROTECTION AGENT WHICH IS A DICARBOXYLIC ACID SEMI-AMIDE OF AN ALKYLENE DIAMINE OR OF EHTYLENE TRIAMINE, OF THE FORMULA R1-NH-((CH2)X-NH)N-CO-R2 WHEREIN R1 IS HYDROGEN, ALKYL, OR ALKYLENE; R2 IS   -CH2-CH2-COOH,-CH=CH-COOH   OR -(1,2-PHENYLENE)-COOH AND N AND X ARE SMALL INTEGERS.

United States Patent US. Cl. 424-319 5 Claims ABSTRACT OF THE DISCLOSURE Cleaning agents comprising anionic surfactants which may tend to irritate the skin in admixture with a skinprotection agent which is a dicarboxylic acid semi-amide of an alkylene diamine or of ethylene triamine, of the formula COR;

wherein R is hydrogen, alkyl, or alkylene; R is -CH CH -COOH, -CH=CHCOOH and n and x are small integers.

The present invention relates to cleaning agents comprising an anionic surfactant and a skin-protective component in admixture therewith.

Some of the surface-active substances used in detergents and cleaning agents may cause irritations on the human skin. These skin lesions are attributed to an interaction of the surfactants and the protein of the skin. This interaction can be easily followed in the special case of anionic surfactants with the enzyme inhibition test described by H. Wilmsmann (Fette, Seifen, Anstrichmittel 65, 958 (1963), 'I. O. Pascual (Afinidad 507, (1966)).

The best way for illustrating the results of this test method is by indication of the concentration of the individual surfactants which, under standardized conditions, causes a 50% inhibition of the enzyme activity. This socalled 50% inhibition value is determined in the most simple manner by extrapolation from a series of concentrations of the surfactant to be tested. The expected compatibility of the detergent with the skin will be the bet ter the higher the 50% inhibition value is.

Now, we have found that, surprisingly, the compatibility of anion surfactants with saccharase, as a measure of the compatibility with the skin, can be essentially improved by a relatively small addition of certain substances, as is shown by the increase of the 50% inhibition values. Especially active is the following class of compounds:

COR; (I)

In the above formula, R represents a hydrogen atom or Patented Apr. 25, 1972 erably 12 to 18 carbon atoms, and R represents one of the groups COOH x represents an integer from 2 to 6, and n stands for the integer 1 or, if x is 2, also for the integer l or 2.

The said compounds can be used as carboxylic acids or alkali metal salts, preferably sodium or potassium salts, or as ammonium salts.

Fatty-alkyl-propylene-diamine semi-amides of maleic acid of the formula CO-GH CH-COOH (II) in which R has the meaning given above, are preferably used.

The compounds may be prepared in simple manner by reacting maleic acid anhydride with a fatty-alkyl propylene-diamine in a benzene solution.

Suitable skin protecting components according to the invention are, for example, coconut fatty-alkylpropylenediame maleic acid semi-amide, hexamethylene-diamine maleic acid semi-amide H N(CH NHCO-CH=CHCOOH and diethylene-triamine maleic acid semi-amide If the skin protecting components of the invention are added to anionic to surfactants, the 50% inhibition value of these surfactants is considerably increased, i.e. their compatibility with saccharase and therewith in general with protein is improved. The quantity of skin-protecting components of the invention to be added to the anionic surfactants can vary within wide limits; it depends on the skin-protecting effect to be attained and on the skinirritating action of the anionic surfactant. In general, the skin-protecting components are added in quantities of about 1 to 25% by weight, referred to the weight of the anionic surfactant. Preferably, they are added in quantities of 1 to 15% by weight, referred to the anionic surfactants.

The following examples show the distinct improvement of the compatibility with saccharase produced by the skinprotecting components of the present invention. The test was effected according to the afore-mentioned enzyme inhibition test.

As skin-protecting component, coconut fatty acid monoethanolamide has been used hitherto. This substance was included in the test series for comparison.

Reagents:

Solution of surfactant: A 0.01 molar solution of the anionic surfactant to be tested was prepared.

Solution of saccharase: 5 ml. of a saccharase solution (Invertin, E. Merck) were made up with distilled water to give ml.

Solution of sugar: 30 g. of sucrose were dissolved in distilled water and made up to 100 m1.

Buffer solution pH 4.0: 25.2 g. of citric acid and 240 ml. of 1N-NaOH were made up with water to about 1 liter. Then, 880 ml. of 0.1 N-hydrochloric acid were added, the whole was mixed and made up with water to exactly 2 liters in a measuring flask. Where necessary, the solution was adjusted to exactly pH 4 by means of sodium hydroxide solution or hydrochloric acid.

Procedure:

A series of concentrations of the anionic surfactant to be tested, in the present case 0.5, 0.6, 0.7 ml. of the 0.01 molar solution, were introduced into measuring flasks having a capacity of 50 ml. (the suitable concentrations were determined by preliminary tests). Then, such a quantity of buffer solution was added that the volume of the incubation batch was exactly 15 ml.

For control tests,

(a) the surfactant solutions were combined with 5 ml. of

distilled water and ml. of buffer solution, and

(b) solutions without surfactant were combined with 5 ml. of saccharase solution and 10 ml. of buffer solution.

The flasks were closed and allowed to stand for 24 hours at 40 C. After 24 hours, 25 ml. of sucrose solution that had been heated to 40 C. were introduced into each flask and each flask was filled up to a volume of 50 ml. with distilled water having a temperature of 40 C. This mixture was introduced into the tube of a polarimeter, the temperature of which was kept constant at 40 C. Sample (a) (without enzyme) gives the starting angle a. This na -value was taken as the starting angle for all tests. Sample (b) (with enzyme, without surfactant) showed the course of a normal sucrose inversion. The rotation angle obtained after 300 minutes was used as 0200 for all tests. For the samples to be tested, the rotation angle (a was determined before it reached the maximum value, in the present case after 60 minutes, and the reaction rate was therefrom calculated as follows:

-1 Percent, reaction rate=w oozoo The inhibition values were then obtained as the difference from 100.

Percent inhibition=l00 percent reaction rate.

The inhibition in percent was determined for each surfactant concentration used. The 50% inhibition value of the respective surfactants was extrapolated graphically therefrom. The surfactant solutions containing added skim protecting components were tested in the same manner The following surfactant solutions were prepared:

Surfactant I 0.382 g. (1 mmol) of the sodium salt of a fatty alcohol-diglycol ether sulfate comprising a mixture of natural C -C fatty alcohols in a proportion of 70:30 Was dissolved in distilled water and filled up to exactly 100 ml.

EXAMPLE 1 Skin-protecting component: Coconut fatty-alkyl-propylene-diamine-maleic acid semi-amide.

0.382 g. (1 mmol) of the sodium salt of a fatty-alcohol-diglycol ether sulfate comprising a mixture of natural G -C fatty alcohols in a proportion of 70:30 and 0.0368 g. (0.1 mmol) of coconut fatty-alkyl-propylene-diaminemaleic acid semi-amide were dissolved in distilled water and filled up to exactly 100 m1.

EXAMPLE 2 Skin-protecting component: Hexamethylene-diaminemaleic acid semi-amide 0.382 g. (1 mmol) of the sodium salt of a fatty-alcohol-diglycol ether sulfate comprising a mixture of'natural C -C fatty alcohols in a proportion of 70: 30 and 0.0214 g. (0.1 mmol) of hexamethylene-diamine-maleic acid semi-amide were dissolved in distilled water and filled up to exactly 100 ml.

EXAMPLE 3 Skin-protecting component: Diethylene-triamine-maleic acid semi-amide 0.382 g. (1 mmol) of the sodium salt of a fatty-alcohol-diglycol ether sulfate comprising a mixture of natural C -C fatty alcohols in a proportion of 70:30 and 0.0201 g. (0.1 mmol) of diethylene-triamine-maleic acid semiamide were dissolved in distilled water and filled up to exactly ml.

EXAMPLE 4 (Comparative test) Skin-protecting component: Coconut fatty acid monoethanol amide 0.382 g. (1 mmol) of the sodium salt of a fatty alcohol diglycol ether sulfate comprising a mixture of natural C1zC14 alcohols in a proportion of 70:30 and 0.0271 g. (0.1 mmol) of coconut fatty acid monoethanol-amide were dissolved in distilled water and filled up to exactly 100 ml.

Surfactant H 0.328 g. (1 mmol) of a secondary alkane-sulfonate having 13 to 17 carbon atoms was dissolved in distilled water and filled up to 100 ml.

EXAMPLE 5 Skin-protecting component: Coconut fatty-alkyl-propylene-diamine maleic acid semi-amide 0.328 g. (1 mmol) of a secondary alkane-sulfonate containing 13 to 17 carbon atoms and 0.368 g. (0.1 mmol) of coconut fatty-alkyl-propylene-diamine-maleic acid semiamide were dissolved in distilled water and filled up to exactly 100 ml.

Surfactant III 0.330 g. (1 mmol) of a-olefin-sulfonate containing 14 to 20 carbon atoms was dissolved in distilled water and filled up to exactly 100' ml.

EXAMPLE '6 Skin-protecting component: Coconut fatty-alkyl-propylene-diamine maleic acid semi-amide.

0.330 g. of a-olefin-sulfonate containing 14 to 20 carbon atoms and 0.0368 g. (0.01 mmol) of coconut fattyalkyl-propylene-diamine-maleic acid semi-amide were dissolved in distilled water and filled up to exactly 100 ml.

Of the above solutions, the 50% inhibition value was determined as described above. The results are compiled in the following table.

1. A cleaning agent consisting essentially of an anionic surfactant causing irritation to the skin and, in admixture therewith, from 1 to 25 percent, by weight of said anionic surfactant, of a skin-protective agent of the formula R,NHE OHZ .-NH1

or an alkali metal salt or ammonium salt thereof, wherein R is hydrogen, or alkyl or alkenyl having 1 to 18 carbon atoms, R is CH -CH -COOH or CH=CH-COOH,

x is an integer from 2to 6 and n is 1, or ifx is 2, n is l or 2.

A cleaning agent as in claim 1 wherein R is --CH CH --CO0H.

3. A cleaning agent as in claim 1 wherein R is --CH=CHCOOH.

4. A cleaning agent as in claim 1 wherein said skinprotective agent is a coconut fatty alkyl-propylene diamine-maleic acid semi-amide or an alkali metal salt or ammonium salt thereof.

5. The method of protecting the skin from anionic surfactants causing irritation to the skin, which method comprises contacting the skin with such an anionic surfactant in the presence of a skin protective agent of the formula or an alkali metal salt or ammonium salt thereof, wherein References Cited UNITED STATES PATENTS OTHER REFERENCES Protein Detergents by R. Richard Riso, Bulletin of Stephan Chemical Co., 1963.

R is hydrogen, or alkyl or alkenyl having 1 to 18 car- 15 LEON ROSDOL, Primary Examiner bon atoms, R is CH CH COOH or CH=CH-COOH x is an integer from 2 t0 6 and n is 1 or 2, said skin protective agent being in admixture with said surfactant and being present in a proportion of from 1 to 25 percent by weight of said anionic surfactant.

D. L. ALBRECHT, Assistant Examiner US. Cl. X.R.

20 252527, 532, 535, 536, 546, 551, 554, 555, Dig. 5; 

